The House will establish a select committee to investigate the terrorist attack in Benghazi, House Speaker John A. Boehner announced Friday, escalating the issue once again and setting up an official inquiry that will keep the politically nettlesome issue in the news for months to come.

Mr. Boehner’s move came just hours after House Oversight Committee Chairman Darrell Issa issued a subpoena to Secretary of State John F. Kerry demanding he come testify about why his department didn’t turn over an email that seemed to show the administration erroneously planning to blame a protest for the 2012 attack, rather than the terrorist group that intelligence and military officials suspected of the assault.

Mr. Boehner, in a statement, said the withholding of that email convinced him it was time to appoint a full special committee to investigate.

“It forces us to ask the question, what else about Benghazi is the Obama administration still hiding from the American people?” the speaker said.

The email in question was from a top national security aide to President Obama, who appeared to be coaching others on how to respond to questions in the wake of the Benghazi attacks.

The aide urged that the focus be placed on an anti-Islam video — though both defense and intelligence community sources at the time had already disregarded the video as the reason for the attack on the U.S. diplomatic post in Benghazi.

The State Department turned over the email to Judicial Watch, a public interest law firm, last month, and only after the group went to court. Mr. Issa had issued a subpoena he says should have included that document nearly a year ago, and yet it was never turned over to Congress.

White House officials first said that the document didn’t cover Benghazi and so shouldn’t have been turned over. But by Thursday they had changed tactics and acknowledged it did refer briefly to Benghazi, and said questions about its release would have to be answered by the State Department.

“Compliance with a subpoena for documents is not a game,” Mr. Issa said in issuing a subpoena, which gives Mr. Kerry no choice but to appear. He could have issued an invitation, which would have given the secretary more leeway, but the subpoena raises the issue to a higher level.

Rep. Elijah E. Cummings, the ranking Democrat on the Oversight Committee, said Mr. Issa was making the congressional investigation more combative than it needed to be by subpoenaing Mr. Kerry to testify.

He said that in 2007, when Democrats subpoenaed then-Secretary of State Condoleezza Rice to testify, it came only after he had repeatedly requested her to appear and after the committee debated and voted on the move. Mr. Cummings pointed out that Mr. Issa voted against issuing that subpoena, saying it was inappropriate.

Mr. Boehner’s move means the House will now vote on whether to create a special committee. That vote could be difficult for some red-state House Democrats up for re-election.

The outlines of what the committee would look like weren’t disclosed, but Mr. Boehner said he wants to see it “work quickly to get answers for the American people and the families of the victims.”

Four Americans, including the U.S. ambassador to Libya, were killed in the assault on the diplomatic outpost in Benghazi.

The special investigative committee will supersede the work done by Mr. Issa and several other committee chairmen who had been looking into Benghazi.

Mr. Boehner’s announcement comes just a day after two of those chairmen — Mr. Issa and House Armed Services Committee Chairman Howard P. “Buck” McKeon — clashed over one of Mr. Issa’s witnesses.

A retired Air Force brigadier general testified to Mr. Issa’s committee on Thursday that the military should have been better prepared to respond to the attack, and that they were waiting for guidance for the State Department, which is one reason they didn’t deploy a response force faster.

Mr. McKeon issued a statement challenging that version, saying that the general wasn’t in a position to know, and saying that his committee’s investigation had shown that wasn’t the case.

That clash of findings underscored the trouble of having multiple committees investigation the same complex issue.